UV (2000 Å) luminosity function of Coma cluster galaxies

The UV (2000 Å) luminosity function (hereafter UV LF) of Coma cluster galaxies, based on more than 120 members, is computed as the statistical difference between counts in the Coma direction and in the field. Our UV LF is an up-date of a preliminary constrain on the UV LF previously computed without the essential background counts. The UV LF is well described by a power law with slope α ∼ 0.46, or equivalently, by a Schechter function with M∗ much brighter than the brightest cluster galaxy and with a slope αS ∼ −2.0 or larger. In spite of what happens in the optical band, low luminosity galaxies give a large contribution to the integral luminosity, and by inference, to the total metal production rate. Galaxies blue in UV − b and/or b−r dominate the Coma cluster UV LF, both in number and luminosity. The major source of error in the estimate of the UV LF cames from the background determination in the Coma direction, which is still uncertain, even though constrained at high and low amplitudes by redshift surveys covering the studied field.